A variety of devices are known that include a touch screen Examples of such devices include smart phones, personal digital assistants (PDA), pagers, personal organizers, and the like. These devices typically include a display module under the touch screen. The display module generates target images associated with menu options, programs, user choices, and other operations. The user controls the device by pressing the touch screen over the target image with a stylus or their finger. The device identifies the location pressed and executes the appropriate operation.
Users often employ a stylus to contact the touch screen for a variety of reasons. A stylus brings less dirt and oil into contact with the screen than a finger. A stylus often has a smaller point than a finger, such that it is a more accurate pointer to insure that the correct operation is initiated. For those devices that permit users to enter alpha-numeric characters by writing them, the stylus' point is necessary to achieve accurate character recognition.
Although a stylus is preferable to a finger for character entry via a touch screen, the stylus is less convenient to transport. It must be stowed in the device or the user must carry it. Users typically prefer to stow the stylus in the device so that it is not lost or forgotten when the device is transported. However, it is difficult to accommodate a stylus in a compact, portable device as it is often critical that these devices be light weight and compact.
For the stylus to be accommodated without comprising the size and weight requirements of the device, the stylus must also be light weight and compact. However, to provide a rigid stylus that is constructed of a single piece of plastic or wood, it is necessary that the stylus be thick. If the stylus is too thin, it will be flimsy and break easily. Additionally, a one piece stylus must have an element that projects out of the device in which it is stored so that a user can grip it to remove the stylus, or an ejection mechanism must be provided on the device to push the stylus out. Projecting elements are disadvantageous as they can get caught on clothes. Eject mechanism are undesirable because of their cost and space requirements.
One alternative to providing a stylus having a one piece construction is to employ a telescoping stylus. However known telescoping styluses require manual actuation to pull them to full extension. Additionally, although they permit storage in the retracted position, they are heavy and thick, requiring a large diameter opening in the device. Because of the large diameter, they necessarily require a relatively large storage volume even when retracted.
Accordingly, there is a need for an improved stylus for portable devices having a touch screen display.